The CI fails because Python 3 is not installed

Summary

The CI unexpectedly started to fail for previously passing jobs. This has been noted in !30 (merged), but the same behavior can be triggered on the HEAD of develop.

The issue likely comes from a change in the dependencies of other packages.

Steps to reproduce

1. Try to re-launch the CI for the HEAD of develop.
2. Wait until it fails

Don't need to do re-launch the CI, it has already been done: https://gitlab.cern.ch/cmsgemonline/cmsgemos/-/commit/153a051c54629c8822e87f23ad4b6580e451b761/pipelines

What is the expected correct behavior?

The same CI should not fail for commits which previously passed it without any issue.

Relevant logs and/or screenshots

One can have a look at job #8368346 for example.

Environment

• Version used: 153a051c
• Operation System: centos:7

Possible fixes

• Explicitly install Python 3 in the CI
• Check there are no other missing dependencies
• Do not make yum quiet, so tracking back the changes is easier